Is there any research showing whether sandwich feedbacks are more effective than other forms of feedback?

Question

So, I've been taught to 'sandwich feedback'. For those that are unfamiliar with the term, it means you start and end with giving compliments, and put the feedback in between those compliments.

For me, this feels very unnatural though and fake though. My gut feeling tells me it's weird to give compliments just so you can say 'this was better done another way'. Also, although the method assumes the compliments given are real, they feel fake to me (both when giving and receiving them).

A google search for the effectiveness of the feedback sandwich gives me a lot of opinion pieces that share my views, but no links to scientific experiments or research.

Is there any research or scientific proof out there on why and how sandwich feedbacks are more effective than other ways of giving feedback?

Answer 1

_{Edit: since some users raised the concern that the question cannot be answered with peer-reviewed articles, I looked for studies in PubMed, an exclusively academic database. The first two studies have been retrieved there.}

- The hard data

Apparently, there have been scientific studies on the topic, although not many. The following two articles looked the most relevant to me.

This paper was published on the peer-reviewed journal "Advances in Health Sciences Education". It studies the effects of sandwich feedback on medical students on clinical patient note-writing assignments. From the Discussion:

These studies indicate that students think feedback sandwiches positively impact their subsequent performance when they do not. [...] We find a consistent placebo dose effect on student perceptions in that full sandwiches are perceived as most effective, followed by ‘open-faced’ sandwiches, followed by unsandwiched feedback. While substantive positive comments resulted in an interim improvement in congruence with calibration content scores this did not result in improved patient note scores in T2.

Does the disconnect between learner perception and impact on performance matter? That is, is there any negative consequence to students misperceiving the impact of sandwiches? Study 2 hints that feedback sandwiches containing more substantive positive comments might actually be detrimental to students’ ability to critically self-assess, since there was a positive relationship between the number of substantive positive comments at T1 and less accurate self-assessment at T2.

• This other article published in "Resuscitation", a journal of the Elsevier group, compares the learning conversation and the sandwich technique in a BLS (Basic Life Support) training course. While they don't differ much in their final effect, the paragraph about instructors feedback is interesting:

Nineteen (40.4%) instructors remarked that the sandwich technique was too structured and repetitive; “Very repetitive—students quickly picked up on pattern of technique and therefore began to ignore it and so it lost its value”. Sixteen (34%) instructors commented that the sandwich technique was awkward to use as candidates naturally wanted to talk about points for improvement first; “Students were quick to think of the negatives rather than the positives of their performance”.

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- A more theoretical approach

This article ("The sandwich feedback method: Not very tasty") is a review on the topic: it provides a good insight on why sandwich feedback arose in the first place and why it isn't such a good idea. It has been published by the Journal of Behavioral Studies in Business, a peer-reviewed journal.

The study focuses on the sandwich feedback in the workplace, where it can become a repeated behaviour that involves the same people (manager and employees), but I think its conclusions can be extended to its use in common environments.

Why the sandwich feedback is used

[L]eaders admitted that they used this particular approach since they find giving negative performance feedback too stressful. Managers found it to be more relaxing by beginning the discussion with the employee by starting first with positive comments.

[...]

Other reasons why leaders may use the sandwich method surround the issues of optimism and being positive. Managers are encouraged to be upbeat based on two fundamental motivational perspectives:

• approach and
• avoidance

The approach perspective holds that individuals move toward those things they find attractive. Matlin & Stang (1978) stated that there could possibly be no virtue more enviable in the United States than to be an optimistic and positive person.

_{[The article appears to give for granted that the sandwich approach was born in the USA.]}

The avoidance perspective holds that individuals try to evade that which they find to be undesirable or disagreeable. This is the case with providing subordinates negative feedback. Such feedback, however, presents a dilemma; most believe it necessary but few want to deliver it (Ilgen & Davis, 2000).

Why the authors consider the sandwich feedback to be ineffective

The article gives a thorough list of both speculation- and literature-based (though it's literature written by managers relying on their personal experience) of why they consider this method to be ineffective. In short, it benefits the manager and not the employee. Over time, moreover, the employee learns to anticipate a reproach when praised and will doubt the honesty of the praise itself - also because the positive qualities of a person will likely stay more or less the same, thus leading the manager to repeat themselves.

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The article also proposes an alternative to the sandwich feedback. While it is obviously focused on a relationship involving hierarchies such as the one between a manager and their employees, I think it's worth reading it:

1. Plan the discussion, when possible.

2. Keep positives and negatives separate.

3. Time discipline so as not to be too soon or too late.

4. Focus on the issue regarding employee behavior.

5. Connect the behavioral issue to how the issue impacts the business.

6. State consequences if behavior does not improve.

7. Identify the proper and required behavioral change that the supervisor expects.

8. Ask how the manager can help the worker.

9. Express confidence in the employee’s ability to improve.

Answer 2

A quick search on Google Scholar found me the following paper by Amy J. Henley & Florence D. DiGennaro Reed: Should You Order the Feedback Sandwich? Efficacy of Feedback Sequence and Timing

I am no psychiologist, and can't really judge the research in-depth, but it looks like they put some effort into it, so here goes.

Participants and Setting

Participants were eight undergraduate students (7 females, 1 male) enrolled in an introductory behavioral science course at a midwestern university who received extra credit for participation. The experimenter was a graduate teaching assistant for six of the eight participants. Participants’ ranged in age from 18 to 43 (M = 23). Experimental sessions took place in a research room (2.21 × 2.03 × 2.44 m) containing a table, a chair, experimental materials, and one bin located on the center-right of the table for completed products. A one-way mirror separated the research room from an observation room of the same dimensions.

Materials

Participants completed four simulated office tasks: folding brochures, stuffing envelopes, collating packets, and filing timesheets. For the folding task, the experimenter instructed participants to fold brochures in half and place each one in the completion bin located on the table. The materials for stuffing envelopes included two flyers announcing a community event and a box of 500 envelopes. The experimenter instructed participants to place one of each flyer in an envelope and place the unsealed envelope in the completion bin. Materials for the third simulated office task, collating packets, included seven pages of a training manual. The experimenter positioned stacks of each page in two horizontal rows centered in front of the participant (four stacks on the top row, three on the bottom) and a stapler in the bottom-right open space. The experimenter instructed participants to gather one page from each stack, staple the packet in the corner, and place the packet in the completion bin. For the remaining task, we created 120 timesheets (four timesheets for 30 employees). The timesheets were pseudo-randomized and placed on the table aside a mobile bin containing 30 hanging files, one for each employee. We grouped files alphabetically by first name. The experimenter instructed participants to identify the name on the timesheet and file the timesheet in the corresponding folder.

Procedure

The three sequences of feedback included (a) the feedback sandwich, or the delivery of a positive statement followed by a corrective statement and another positive statement (PCP); (b) a positive–positive–corrective (PPC) sequence; and (c) a corrective–positive–positive (CPP) sequence. We selected these sequences to hold the ratio of positive to corrective statements constant and only vary the delivery sequence.1 We also evaluated the effects of no feedback as a control condition. Four participants received feedback about their prior performance immediately before completing the next session of the same task (i.e., presession feedback). The remaining four participants received feedback immediately after the completion of each session (i.e., postsession feedback).

Baseline

On arriving for the first session, participants provided informed consent and demographic information. We asked them to refrain from using their mobile devices during sessions. The experimenter presented the materials on the tabletop, provided instructions about how to perform each task, and asked participants to complete the task. During each session, the experimenter observed the participant through a one-way mirror. After 5 min, the experimenter knocked on the window to prompt the participant to stop performing the task, entered the research room, gathered the session materials, and began the next session. Participants did not receive feedback for any of the tasks. Baseline continued until the participant completed each of the four tasks a minimum of three times and the rate of performance was stable.

Their conclusions were as follows:

The purpose of this study was to evaluate the efficacy of feedback sequence—in particular the feedback sandwich method—and the influence of the timing of feedback delivery. Overall, the findings suggest that the sequence of feedback statements and their timing influence performance, but the effects may be idiosyncratic across participants at the individual level. However, interesting findings emerge when we compare aggregate performance. For participants who experienced presession feedback, the no feedback condition was the most efficacious and the PPC sequence was the least efficacious. For participants who received postsession feedback, the CPP sequence was the most efficacious and the no feedback condition was the least efficacious. Although the most and least efficacious feedback sequences differed for the pre- and postsession feedback conditions when we considered all conditions, there were no statistically significant differences in performance based on feedback timing within a particular feedback sequence, except for the no feedback condition.

More details and more elaborate discussion can be found in the link above.

So to answer your question, there is at least some research done to test the validity of the feedback sandwich, but it doesn't seem all too convincing there is a real benefit.